Adsorption of Textile Dye on Zinc Stannate Oxide: Equilibrium, Kinetic and Thermodynamics Studies

Abstract

Zn 2 SnO 4 powder was prepared by hydrothermal process at 200 C for 12 h. The material was characterized by X-ray-diffraction and surface area. The synthesized sample presented a pure phase and a surface area of 48.8 m 2 Á g À1 . It was used as adsorbent to remove the Reactive Red 141 that is a azo textile dye. The adsorption kinetics of the textile dye on Zn 2 SnO 4 followed the pseudo-secondorder model. The adsorption process was found to be controlled by both external mass transfer and intraparticle diffusion. The equilibrium data were in good agreement with both Langmuir and Freundlich isotherms. Thermodynamic parameters were calculated, and the results revealed that the adsorption process is endothermic in nature, with weak forces of the Van der Walls acting.

Equilibrium, kinetics and thermodynamic study on adsorption of reactive blue-21 and reactive red-141 by chitosan-organically modified nanoclay (Cloisite 30B) nano-bio composite

“…The maximum monolayer adsorption capacity (q m ) calculated from Langmuir isotherm was found to be 476.19 mg/g for RB-21 and 439.30 mg/g for RR-141 respectively. The monolayer adsorption capacity (q m ) of various other adsorbents reported in literature is shown in Table 3 [39][40][41][42][43][44][45][46][47][48][49][50]. The adsorption capacity of the earlier reported adsorbents showed was lower than chitosan clay nanocomposite, reflecting a promising future for the utilization of the nanocomposite in the removal of reactive dyes from aqueous solution.…”

Adsorptive removal of cationic dye from aqueous solution using chemically modified African Border Tree (<i>Newbouldia laevis</i>) bark

“…The Langmuir isotherm model: The Langmuir isotherm model for monolayer adsorption has gained wide application to dye sorption process. It is applicable to homogeneous systems where there is no interaction between the adsorbate molecules (Foletto et al 2011 Where Ao is the Langmuir maximum adsorption capacity (mg/g) and b is the Langmuir constant related to the binding site affinity and the adsorption energy in Lmol -1 , qe, is the adsorption capacity at equilibrium (mg/g) and Ce is the equilibrium concentration of Safranin O (mg/L) in solution. From Table 2, the maximum adsorption capacity for the adsorption of Safranin O unto SMABT is 90.9 mg/L.…”

Photocatalytic activity of zinc stannate: Preparation and modeling

“…(αhϑ ) n = K(hϑ − Eg) (4) where hϑ is the photoenergy, α is the absorption coefficient, K is a constant relative to the material, and n decides the characteristics of the transition in a semiconductor. The exponent n takes on values 2 and 0.5 when the transitions are direct-allowed, and indirectallowed, respectively.…”

“…Zinc stannate, also called zinc-tin oxide (ZTO), is an n-type transparent semiconductor material with a band gap energy of 3.6 eV, a typical inverse spinel structure and high electron mobility which make it suitable for wide range of potential applications, including gas sensing material [1,2], anode materials for batteries [3] adsorbent [4] and photocatalyst [5][6][7][8][9] for dye removal.…”